Method of making vacuum insulated glass (vig) window unit including activating getter

ABSTRACT

Methods of making vacuum insulated glass (VIG) window units are provided, including activating getters in a process of making VIG window units. In certain example embodiments, at least one getter is activated during and/or at the end of a pump-out/evacuation process in which the cavity between the substrates is evacuated. In certain example embodiments, the getter(s) may be activated (e.g., by at least a laser beam that is directed through a pump-out tube) during and/or at the end of the evacuation process in which the cavity between the substrates is evacuated to a low pressure that is below atmospheric pressure.

This disclosure relates generally to vacuum insulated glass (VIG) windowunit configurations and methods for making VIG window units. Thedisclosure more particularly relates to techniques for activatinggetters in a process of making VIG window units. In certain exampleembodiments, at least one getter is activated during and/or at the endof a pump-out process in which the cavity between the substrates isevacuated (e.g., pumped-down). Getters are typically subdivided into twomain classes: evaporable getters (EGs) and non-evaporable getters(NEGs). While this disclosure is applicable to both EG and NEG typegetters, it is particularly useful for getters including NEG type gettermaterial which tend to have a lower activation temperature(s).

BACKGROUND AND SUMMARY OF EXAMPLE EMBODIMENTS

Vacuum insulating glass (VIG) window units typically include at leasttwo spaced apart glass substrates that enclose an evacuated low-pressurespace/cavity therebetween. The substrates are interconnected by aperipheral edge seal and typically include spacers between the glasssubstrates to maintain spacing between the glass substrates and to avoidcollapse of the glass substrates that may be caused due to the lowpressure evacuated environment that exists between the substrates. Someexample VIG configurations are disclosed, for example, in U.S. Pat. Nos.5,657,607, 5,664,395, 5,657,607, 5,902,652, 6,506,472 and 6,383,580 thedisclosures of which are all hereby incorporated by reference herein intheir entireties.

FIGS. 1 and 2 illustrate a conventional VIG window unit 1 and elementsthat form the VIG window unit 1. For example, VIG unit 1 may include twospaced apart substantially parallel glass substrates 2, 3, which enclosean evacuated low-pressure space/cavity 6 therebetween. Glass sheets orsubstrates 2, 3 are interconnected by a peripheral edge seal 4 which maybe made of fused solder glass, for example. An array of supportpillars/spacers 5 may be included between the glass substrates 2, 3 tomaintain the spacing of glass substrates 2, 3 of the VIG unit 1 in viewof the low-pressure space/gap 6 present between the substrates 2, 3.

A pump-out tube 8 may be hermetically sealed by, for example, solderglass 9 to an aperture/hole 10 that passes from an interior surface ofone of the glass substrates 2 to the bottom of an optional recess 11 inthe exterior surface of the glass substrate 2, or optionally to theexterior surface of the glass substrate 2. A vacuum is attached topump-out tube 8 to evacuate (e.g., pump-down) the interior cavity 6 to alow pressure that is less than atmospheric pressure. After evacuation ofthe cavity 6, a portion (e.g., the tip) of the tube 8 is melted to sealthe vacuum in low pressure cavity/space 6. The optional recess 11 mayretain the sealed pump-out tube 8.

As shown in FIGS. 1-2, a getter 12 may be included within a recess 13that is disposed in an interior face of one of the glass substrates,e.g., glass substrate 2. The getter 12 may be used to absorb and/or bindwith certain residual impurities that may remain after the cavity 6 isevacuated and sealed. The getter is of or includes a mixture of metalsthat can react with gas(es) to hold gas(es) impurities to the getteringsurface and/or dissolve such gas(es).

Disclosed herein are techniques for activating getters in a process ofmaking VIG window units. In certain example embodiments, at least onegetter is activated during and/or at the end of a pump-out process inwhich the cavity between the substrates is evacuated.

In certain example embodiments of this invention, there is provided amethod of making a vacuum insulated glass (VIG) window unit, the methodcomprising: having first and second substantially parallel glasssubstrates, a plurality of spacers and a seal provided between the firstand second substrates, a cavity to be evacuated to a pressure less thanatmospheric pressure located between the glass substrates, and at leastone getter provided in the cavity; and activating the getter duringand/or substantially at an end of an evacuation process in which thecavity is evacuated to a pressure less than atmospheric pressure.

In certain example embodiments of this invention, there is provided amethod of making a vacuum insulated glass (VIG) window unit, the methodcomprising: having first and second substantially parallel glasssubstrates, an array of spacers and a seal provided between the firstand second substrates, and a cavity to be evacuated to a pressure lessthan atmospheric pressure located between the glass substrates, and agetter supported by the first substrate; and directing a laser beamthrough a pump-out tube supported by the second substrate so that thelaser beam impinges upon the getter and activates the getter.

These and other embodiments and advantages are described herein withrespect to certain example embodiments and with reference to thefollowing drawings in which like reference numerals refer to likeelements throughout the several views, and wherein:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross sectional schematic diagram of a conventional VIGunit;

FIG. 2 is a top plan view of the conventional VIG unit of FIG. 1;

FIG. 3 is a schematic partial cross sectional diagram illustrating anexample VIG window unit and a technique for activating a getteraccording to an example embodiment of this invention; and

FIG. 4 is a schematic partial cross sectional diagram illustrating anexample VIG window unit and a technique for activating a getteraccording to another example embodiment of this invention.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

Certain example embodiments will be described in detail herein withreference to the foregoing drawings in which like reference numeralsrefer to like elements throughout the several views. It will beunderstood that the embodiments described herein are intended to beillustrative, not limiting, and that those skilled in the art willunderstand that various modifications may be made without departing fromthe true spirit and full scope of the claims appended hereto.

With reference to FIG. 3, a schematic cross sectional view of an exampleVIG window unit 1 is illustrated. VIG window units 1 may be used, forexample, and without limitation, as windows in residential homes, officebuildings, apartment buildings, doors, and/or the like. The VIG windowunit 1 includes spaced apart first and second transparent andsubstantially parallel glass substrates 2, 3 that may be interconnectedby an edge seal 4, which may, for example, and without limitation, be ofor include a vanadium based or VBZ type seal or a solder glass typeseal. Example vanadium based or VBZ type seal compositions are disclosedin U.S. patent application Ser. No. 13/354,963, filed Jan. 20, 2012, thedisclosure of which is incorporated by reference herein in its entirety.VBZ (e.g., vanadium, barium, zinc) based seal compositions are discussedin Ser. No. 13/354,963, and may be used for the edge seal 4 and/or fritbased tube seal 9 in certain example embodiments. Conventional solderglass frit material may also be used for the hermetic edge seal 4 and/orthe frit based tube seal 9 in certain example embodiments. When usingVBZ type seal compositions, a lower temperature sealing thermal profileis used to maintain the desired temper of the glass of the VIG unitbecause VBZ compositions have a lower firing temperature (e.g., <250°C.) than certain other conventional glass frit compositions that may beused to form seals in VIG units. It will be understood that theembodiments disclosed herein are equally applicable to VIGconfigurations using any suitable seal material.

In certain embodiments, the transparent glass substrates 2, 3 may beapproximately the same size. However, in certain other exampleembodiments, one glass substrate 2 may be larger than the other 3 toprovide, for example, an approximately L-shaped step proximate an edgeof the VIG unit. One or both of the glass substrates 2, 3 may alsooptionally include at least one coating material (not shown) such as,for example, and without limitation, a low-E coating. It will beunderstood that various coatings may be present on an interior surfaceof at least one of the glass substrates 2, 3, and that such coatingsprovide various beneficial performance characteristics to the VIG windowunit 1. In certain example embodiments, a low-E coating for blocking IRradiation is provided on the interior surface 3 a of substrate 3 (asopposed to substrate 2 which supports the getter(s)). In certain exampleembodiments, the VIG window unit has a visible transmission of at leastabout 30%, more preferably of at least about 40%, even more preferablyof at least about 50%, and even more preferably of at least about 60% or70%.

An array of support pillars/spacers 5 is located between the glasssubstrates 2, 3 to maintain the spacing of the substrates in view of thelower than atmospheric pressure that is ultimately provided in lowpressure evacuated cavity/space 6 between the substrates 2, 3. Incertain example embodiments, the spacers may have a height, for example,of about 0.1 to 1.0 mm, more preferably from about 0.2 to 0.4 mm. Theheight of the spacers 5 may approximately define the height of thevacuum/evacuated cavity 6. As noted above, the spacers 5 are preferablyof a size that is sufficiently small so as to be visibly unobtrusive.According to certain example embodiments, the spacers 5 may be made ofor include solder glass, glass, ceramic, metal, polymer, or any othersuitable material. Additionally, the spacers 5 may be, for example,generally cylindrical, round, spherical, dime-shaped, C-shaped,pillow-shaped or any other suitable shape.

A pump-out tube 8, that may be hermetically sealed for example usingsolder glass 9, is provided through a hole 22 in one of the glasssubstrates, e.g., substrate 3. The pump-out tube 8 is used in a processto evacuate the cavity 6 between the substrates 2, 3, such as, forexample, by attaching a vacuum pump to the distal end of pump-out tube 8and evacuating the cavity 6 to a low pressure, e.g., a pressure lowerthan atmospheric pressure. Alternatively, the cavity may be evacuated ina low-pressure chamber. In a preferred example, a pressure in the cavity6 following evacuation is, for example, preferably below about 10⁻²Torr, and more preferably below about 10⁻³ Torr, and even morepreferably below about 5×10⁴ Torr. During the evacuation process, theVIG unit may be subject to heating to help with the evacuating process,e.g., temperature(s) from about 150-300 degrees C. After evacuating thecavity 6, the pump-out tube 8 may be sealed, for example, by melting thetip 8 a of the tube 8 by any suitable means, such as, for example, bylaser. According to certain example embodiments, the pump-out tube 8 mayor may not fully extend through the hole 22 to be flush with theinterior surface 3 a of the glass substrate 3, and may be left justshort of the interior surface 3 a by a distance of, for example, andwithout limitation, up to about up to 0.1 mm from the interior surface 3a in certain example embodiments.

After the pillars/spacers 5 are positioned on bottom glass substrate 2,at least one getter (e.g., EG type) 32 is positioned in getter recess14. Then, the edge seal material is deposited on substrate 2. The othersubstrate 3 is brought down on substrate 2 so as to sandwichspacers/pillars 5, the glass frit solution, and getter 32 between thetwo substrates 2, 3. The assembly including the glass substrates 2, 3,the spacers/pillars 5, getter 32, and the edge seal material is thenheated to a temperature (e.g., of at least about 500° C.) at which pointthe edge seal material melts, wets the surfaces of the glass substrates2, 3, and ultimately forms a hermetic peripheral/edge seal 4.

After formation of the edge seal 4 between the substrates, a vacuum isdrawn via the pump-out tube 8 to form low pressure space/cavity 6between the substrates 2, 3. To maintain the low pressure in thespace/cavity 6, substrates 2, 3 are hermetically sealed via edge seal 4,and the small spacers/pillars 5 are provided between the substrates tomaintain separation of the approximately parallel substrates againstatmospheric pressure. Once the space 6 between substrates 2, 3 isevacuated, the pump-out tube 8 may be sealed, for example, by meltingits tip using a laser or the like. After evacuation of the cavity/space6 to a pressure less than atmospheric, sealing of the pump-out tube maybe accomplished by heating an end 8 a of the pump-out tube 8 to melt theopening and thus seal the cavity of the VIG window unit. For example andwithout limitation, this heating and melting may be accomplished bylaser irradiation of the tip 8 a of the pump-out tube 8.

In various embodiments herein, the substrates 2 and/or 3 of or includingglass may be from about 1-6 mm thick, more preferably from about 3-5 mmthick, with an example glass thickness being about 4 mm. In variousembodiments herein, recess 14 may have a depth of from about 1.5 to 2.5mm, with an example recess depth being about 2 mm in an example 4 mmthick sheet of glass. In certain example embodiments of forming thesubstrates 2 and 3, the getter recess(es) 14 is/are formed in one of therespective glass sheets, then the glass sheets may optionally bethermally tempered, then optionally a low-E coating may be provided onan interior surface of one of the substrates, then the two substrates 2,3 (including any low-E coating, not shown) may be brought togetheraround edge seal material and spacers as discussed herein during the VIGformation process.

Referring to FIGS. 3-4, during the evacuation process when the pressureof cavity/space 6 is being lowered, the VIG unit is subjected to heatingto help with the evacuating process, e.g., heated to and/or intemperature(s) from about 150-300 degrees C. Certain example embodimentsof this invention relate to activating the getter(s) 32 during and/or atthe end of the evacuation process. Thus, one or more getters 32 areactivated during and/or at the end of the VIG pump out process. This isbeneficial, for example, for getters including NEG type getter materialas such getters typically need to be heated for some period of time tobecome activated (e.g., from about 350-500 degrees C. for about 5-15minutes, with an example being at about 400 degrees C. for about 10minutes). Because the VIG unit is already heated (e.g., to about 150-300degrees C.) due to the heating used in the pump-out evacuation process,the energy and time needed to activate the getter 32 can be reduced byperforming the activation during the evacuation process. Moreover, ifconducted during the evacuation process, all or a portion of the timerequired for activation can overlap time required for evacuation (e.g.,from about 3-12 minutes), thereby reducing the time needed to make theVIG window unit. By carrying out both evacuation and getter activationin overlapping manners (i.e., at least partially at the same time),throughput of an inline fabrication process of fixed length and linespeed can be increased.

Getter 32 absorbs and/or binds with certain residual impurities (e.g.,undesirable gases such as CO₂ and N₂) that may remain and/or are presentin the cavity 6 during and/or after evacuation. The getter 32 may belocated in a getter container in the getter recess 14, or alternativelymay be deposited or located directly on the substrate 2 in differentexample embodiments of this invention. Getter 32, for purposes ofsimplicity, is illustrated as-deposited in non-activated form. Gettersare typically subdivided into two main classes: evaporable getters (EGs)and non-evaporable getters (NEGs). EGs often include one or morealkaline earth metal(s) calcium, strontium, and/or especially barium.NEGs often include titanium, zirconium, or alloys thereof with one ormore metals selected amongst aluminum and metal(s) of the firsttransition row. Both getter types, EGs and NEGs, require activation byheating for their operation to remove from the getter surface variousoxides, carbides, and/or nitrides that otherwise inhibit the gaseousspecies to be removed from being sorbed on the getter's surface. Becauseof their high reactivity toward atmospheric gases, getters are typicallymade and transported in inactive form and require a suitable activating(e.g., flashing) heat treatment once they are arranged in the space tobe evacuated. The getter 32 in the FIG. 3 and FIG. 4 embodiments may bean EG type getter or an NEG type getter. Alternatively, in certainexample embodiments of this invention, the getter 32 may be a hybridgetter including both EG and NEG material.

Getter 32 can be provided below the pump-out tube 8 and at leastpartially in getter recess 14 in the glass substrate 2 as shown in FIG.3, being deposited in solid form, so as to enable the laser beam to heatthe getter through the tube 8. The location below the pump-out tube 8 isalso advantageous because it allows for more scattering of the gettermaterial during activation/flashing (e.g., in the case of EG) therebyresulting in more active getter surface area.

In the FIG. 3 embodiment, during and/or at the end of the evacuationprocess, a laser 30 (e.g., YAG laser) used to seal the tip of thepump-out tube 8 can also be used to heat the getter(s) in order toactivate the getter(s) 32. The tip-off laser 30 can be used to furtherheat the getter 32 from the elevated evacuation temperature to itsactivation temperature. The laser can be aimed through the bore of thepump-out tube 8 so that the laser beam 31 emitted from the laser 30 goesthrough the tube 8 and hits the getter 32 in order to further heat thegetter to activation temperature(s). The laser beam 31 may be directedthrough the pump-out tube 8 toward the getter 32 when the VIG unit islocated in a vacuum chamber (not shown) so that the pressure in thecavity 6 does not significantly rise when the laser beam is beingdirected toward the getter for getter activation. As can be seen in theFIG. 3 embodiment, the getter 32 can be located substantially directlybelow the pump-out tube 8. At elevated temperature(s), contaminants onthe surface of a NEG type getter diffuse into the bulk of the getterproducing fresh reactive getter surface material for getteringundesirable gas(s) in cavity 6. By creating cracks in an NEG typegetter, residual gas(es) in the cavity 6 gain passage to the getter coreor interior whereby they are trapped and/or absorbed. Though theexposure area where the laser beam exposes the getter 32 may be afraction of the getter size, most or all of NEG type getters 32 can beheated gradually through internal heat conduction in such a manner inorder to cause getter activation, and/or the laser can be used to shockheat the getter thereby creating cracks therein to exposure getteringsurface area; and regarding EG type getters when the spot hit by thelaser exceeds the threshold temperature the exothermic reaction startsfor the EG material and heats the EG to the point where getterablecomponents (e.g., Ba, Ca and/or Sr) are evaporated and deposited uponadjacent surface(s). After the getter 32 has been activated (e.g.,flashed) by the laser beam from laser 30, the same laser can be used toseal (tip-off) the top of the pump-out tube 8. In certain exampleembodiments, the laser beam 31 impinges upon the getter 32 for fromabout 2-15 seconds, more preferably from about 3-10 seconds, in order toactivate the getter 32, and thereafter impinges upon the tip 8 a of thepump-out tube 8 for from about 20-30 seconds in order to seal off thetip of the tube thereby sealing the cavity 6. The same laser power maybe used in both getter activation and tube tip-off in certain exampleembodiments. Example tip-off techniques for sealing off the top of thetube 8 via laser are described in U.S. Ser. No. 13/474,819, filed May18, 2012, the entire disclosure of which is hereby incorporated hereinby reference.

Upon heating, activation for an EG type getter 32 includes evaporationof the metal (e.g., barium) onto the inner surfaces of the VIG unit,including onto the vertical, rounded or tilted sidewalls of recess 14and/or onto the inner major surfaces of substrates 2, 3, and possiblyinto part of tube 8. Barium evaporation can be carried out by heatingthe EG 32 in accordance with the FIG. 3 or FIG. 4 embodiments, e.g., vialaser through the pump-out tube 8, and/or from outside the VIG unit byexposing the EG to RF radiation from a coil and/or to microwaveradiation. For example, when the EG composition of the getter includesBaAl₄ and Ni for example, exposure of the getter material to the laserand/or radiation for activation causes an increase in temperature of thepowders to about 800-850 degrees C. At these temperatures, an exothermicreaction takes place between BaAl₄ and Ni, that causes a further rise intemperature to about 1100-1200 degrees C., at which temperature bariumfrom the EG evaporates. The metal condenses in the form of a film on theadjacent inner surfaces of the VIG unit according to a so-called flashphenomenon, with the evaporated barium inclusive film being an activeelement in the gettering of undesired gases from the evacuated cavity 6.Thus, activation of the EG 32 causes the getter material to scatter toand become evaporated on adjacent areas inside the VIG unit viaevaporation thereby increasing the surface area of gettering material.Thus, following activation/flashing, evaporated getter material isprovided on the vertical, rounded or tilted sidewalls of getter recess14 and/or on the inner major surface(s) of substrates 2 and/or 3proximate the recess 14, and possibly into part of tube 8 and/or thesidewall of the hole for the tube 8.

An EG type getter 32 may be made of any suitable material that functionsas an evaporable getter. Such materials include, but are not limited to,compounds comprising an element(s) chosen from among calcium, strontium,and barium. Preferably such compounds are in the form to limit thereactivity of these elements to air. An example useful EG material for agetter is an intermetallic compound BaAl₄, which further may be admixedwith nickel powder and possibly small quantities of one or more of Al,Fe, Ti and/or their alloys. Other EG materials will be familiar to thoseof skill in the art. Activation causes the evaporated getter material toform in and/or adjacent the recess 14, with evaporated getter materialbeing the getter material that is present (e.g., present in/on one ormore of: getter recess sidewall(s), getter recess, interior majorsurface(s) of one or both substrates proximate the getter recess, and/orpump-out tube recess and/or tube itself) following activation and/orflashing of getter that included EG type material.

Non-evaporable getter (NEG) material can also be used for getter 32 inFIGS. 3-4, and can be any material known to those of skill in the art tofunction as a non-evaporable getter. For example, such NEG materials caninclude alloys comprising zirconium (Zr), titanium (Ti), or mixturesthereof, and at least one other element chosen from among vanadium (V),chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni),aluminum (Al), niobium (Nb), tantalum (Ta), and tungsten (W). In certainexample embodiments, zirconium-based alloys may be used, such as thebinary alloys Zr—Al, Zr—Fe, Zr—Ni, Zr—Co, or the ternary alloys Zr—V—Feand Zr—Mn—Fe. For example, NEG getters such as those commercially soldby SAES Getters, based in Italy, under tradenames St 101 and St 707.Another example NEG getter material which may be used has a percentageweight composition of substantially Zr 76.6%-Fe 23.4%, or Zr 75.7%-Ni24.3%. Activation of an NEG 32, in accordance with FIG. 3 and/or FIG. 4,can substantially remove and/or interrupt the thin layer of oxides,carbides and/or nitrides that accumulates on the surface of the NEGmaterial when the material is exposed to air. Activation, e.g., vialaser and/or microwave, allows these species to migrate towards thegetter particle core for NEG material, thereby exposing a metal orsubstantially metal surface which is active in gas chemisorption. Theactivation temperature for NEG material depends on the NEG composition,and can vary from about 350 degrees C. for an alloy having a weightcomposition of substantially 70% Zr, 24.6% V, 5.4% Fe, to about 900degrees C. for an alloy characterized by 84% Zr, 16% Al.

This invention is not limited to activating the getter 32 by a laserbeam aimed through the pump-out tube as shown in FIG. 3. In otherexample embodiments (e.g., see FIG. 4), the getter(s) 32 can beactivated using other techniques during and/or at the end of theevacuation process, including but not limited to (i) via a laser beamthat is emitted from a laser and proceeds through one of the glasssubstrates before hitting the getter, where such laser beam does notproceed though the length of the pump-out tube, (ii) by localizedmicrowave heating via a microwave source located outside the VIG unit,and/or (iii) by localized RF-inductive heating from a coil locatedoutside the VIG unit. These techniques (i)-(iii) for heating the getter32 to activation temperature(s)/point are particularly useful when thegetter(s) 32 is not located directly under the pump-out tube 8. Asexplained above, these techniques are preferably performed during and/orat the end of the evacuation (e.g., pump-out) process for the reasonsexplained above. FIG. 4 illustrates several such embodiments. FIG. 4 isthe same as FIG. 3, except that in the FIG. 4 embodiment the getter 32is activated by heating due to one or both of (a) by localized microwaveheating via a microwave source 50 located outside the VIG unit, and/or(b) by localized RF-inductive heating from a coil 50′ located outsidethe VIG unit.

When the getter activation is performed in parallel to the evacuation(e.g., pump-out) process, the activation of the getter 32 (whether bylaser, induction or microwave heating) can be sequenced so that thegetter is not significantly further poisoned by residual gases in thecavity 6. When gradually heated, the technique may be designed so thatthe getter 32 does not exceed the temperature at which it begins to sorp(which temperature depends on the getter composition) during evacuation(e.g., pump-out) before the pressure drops to or below about 1×10⁻² to1×10⁻³ mbar. When shock heating is used to produce cracks in a getterincluding NEG material, the pressure in the cavity 6 should be close tothe minimum pressure achieved during evacuation (e.g., pump-out), suchas less than or equal to about 1×10⁻³ mbar, before the shock heating isdesigned to produce the cracks.

Producing cracks in the getter 32 for the purpose of exposing reactivebulk material for gettering may be facilitated by incorporating highexpansion material within the bulk of the getter in certain exampleembodiments. The high expansion material could be a gas, liquid, or highCTE solid. Liquids or solids with transitions to high expansion phasesoccurring above the highest processing temperature (e.g., frit firing)may be used.

In certain example embodiments of this invention, there is provided amethod of making a vacuum insulated glass (VIG) window unit, the methodcomprising: having first and second substantially parallel glasssubstrates, a plurality of spacers and a seal provided between the firstand second substrates, and a cavity to be evacuated to a pressure lessthan atmospheric pressure located between the glass substrates, and agetter supported (directly or indirectly) by the first substrate; anddirecting a laser beam (focused, non-focused, or parallel) through apump-out tube supported (directly or indirectly) by the second substrateso that the laser beam impinges upon the getter and activates thegetter.

In the method of the immediately preceding paragraph, said directing thelaser beam through the pump-out tube to activate the getter may beperformed during and/or substantially at an end of an evacuation processin which the cavity is evacuated to a pressure less than atmosphericpressure.

In the method of any of the preceding two paragraphs, said directing thelaser beam through the pump-out tube to activate the getter may beperformed at least during an evacuation process in which the cavity isevacuated to a pressure less than atmospheric pressure.

In the method of any of the preceding three paragraphs, said directingthe laser beam through the pump-out tube to activate the getter may beperformed at least substantially at an end of an evacuation process inwhich the cavity is evacuated to a pressure less than atmosphericpressure.

In the method of any of the preceding four paragraphs, said directingthe laser beam through the pump-out tube to activate the getter may beperformed so that the getter does not exceed a temperature at which itbegins to absorb undesirable gas(es) before pressure in the cavity dropsto or below about 1×10⁻² to 1×10⁻³ mbar during an evacuation process.

In the method of any of the preceding five paragraphs, said directingthe laser beam through the pump-out tube to activate the getter may beperformed after an evacuation process causes pressure in the cavity toreach less than or equal to about 1×10⁻³ mbar.

In the method of any of the preceding six paragraphs, the getter may belocated in a recess defined in the first substrate.

In the method of any of the preceding seven paragraphs, the getter maybe located directly below the pump-out tube when the VIG unit is viewedin cross section.

In the method of any of the preceding eight paragraphs, the getter maycomprise barium or including NEG material.

In the method of any of the preceding nine paragraphs, the VIG windowunit may have a visible transmission of at least about 50%.

In certain example embodiments of this invention (e.g., see FIGS. 3-4),there is provided a method of making a vacuum insulated glass (VIG)window unit, the method comprising: having first and secondsubstantially parallel glass substrates, an array of spacers and a sealprovided between the first and second substrates, a cavity to beevacuated to a pressure less than atmospheric pressure located betweenthe glass substrates, and at least one getter provided in the cavity;and activating the getter during and/or substantially at an end of anevacuation process in which the cavity is evacuated to a pressure lessthan atmospheric pressure.

In the method of the immediately preceding paragraph, said activatingthe getter may be performed at least during the evacuation process inwhich the cavity is evacuated to a pressure less than atmosphericpressure.

In the method of any of the preceding two paragraphs, said activatingthe getter may be performed at least substantially at an end of theevacuation process in which the cavity is evacuated to a pressure lessthan atmospheric pressure.

In the method of any of the preceding three paragraphs, said activatingmay comprise directing a laser beam through a pump-out tube supported bythe second substrate so that the laser beam impinges upon the getter andactivates the getter, where the getter is supported by the firstsubstrate.

In the method of any of the preceding four paragraphs, said activatingmay comprise directing a laser beam at the getter in order to at leasthelp activate the getter.

In the method of any of the preceding five paragraphs, said activatingmay comprise emitting microwave radiation from a microwave source towardthe getter in order to at least help activate the getter.

In the method of any of the preceding six paragraphs, said activatingmay comprise emitting RF radiation from at least a coil toward thegetter in order to at least help activate the getter.

In the method of any of the preceding seven paragraphs, said activatingmay be performed so that the getter does not exceed the temperature atwhich it begins to sorp before pressure in the cavity drops to or belowabout 1×10⁻² to 1×10⁻³ mbar during an evacuation process.

In the method of any of the preceding eight paragraphs, said activatingmay be performed after an evacuation process causes pressure in thecavity to reach less than or equal to about 1×10⁻³ mbar.

In the method of any of the preceding nine paragraphs, the getter may belocated directly below a pump-out tube when the VIG unit is viewed incross section.

In the method of any of the preceding ten paragraphs, the VIG windowunit may have a visible transmission of at least about 50%.

While certain example embodiments have been described and disclosedherein, it will be understood that the embodiments described herein areintended to be illustrative, not limiting, and that those skilled in theart will understand that various modifications may be made withoutdeparting from the true spirit and full scope of the claims appendedhereto.

1-22. (canceled)
 23. A method of making a vacuum insulated glass (VIG)window unit, the method comprising: having first and secondsubstantially parallel glass substrates, a plurality of spacers and aseal provided between the first and second substrates, a cavity to beevacuated to a pressure less than atmospheric pressure located betweenthe glass substrates, and at least one getter provided in the cavity;activating the getter via at least radiation from an inductive coil,said coil being located outside of the cavity, during and/orsubstantially at an end of an evacuation process in which the cavity isevacuated to a pressure less than atmospheric pressure; wherein thecavity to be evacuated is located between opposing substantiallyparallel major surfaces of the first and second substrates respectively,and wherein a pump-out tube for evacuating the cavity extends in adirection substantially perpendicular to the major surfaces of the firstand second substrates, and wherein the pump-out tube extends through atleast part of one of the substrates, the pump-out tube being elongatedso that the pump-out tube has a length longer than its width.
 24. Themethod of claim 23, wherein said activating the getter is performed atleast during the evacuation process in which the cavity is evacuated toa pressure less than atmospheric pressure.
 25. The method of claim 23,wherein said activating the getter is performed at least substantiallyat an end of the evacuation process in which the cavity is evacuated toa pressure less than atmospheric pressure.
 26. The method of claim 23,wherein said activating is performed only after an evacuation processcauses pressure in the cavity to reach less than or equal to about1×10⁻³ mbar.
 27. The method of claim 23, wherein the getter is locateddirectly below the pump-out tube, and the getter is located between thecoil and the pump-out tube, when the VIG unit is viewed in crosssection.
 28. The method of claim 23, wherein the VIG window unit has avisible transmission of at least about 50%.